RFR: 8220674: [TESTBUG] MetricsMemoryTester failcount test in docker container only works with debug JVMs

[Bob Vandette]

Please review this fix for a container test that fails on some Linux distributions.

The test fails to see the Memory Fail count metric value increase.  This is caused by
the fact that we are allowing ergonomics to select the amount of Heap size.  This 
size varies depending on the amount of free memory that’s available on different
docker implementations.  

The fix is to force the VM to always set the heap size to the size of the containers
memory.  This change also stops allocating once it sees the fail count increase.
This is needed to keep the container from getting killed by the out of memory
killer.

The fix has been verified by the submitter along with a local run of the container tests.

BUG:

https://bugs.openjdk.java.net/browse/JDK-8220674

WEBREV:

http://cr.openjdk.java.net/~bobv/8220674/webrev/

Bob.